cifs: fix smb3_zero_range so it can expand the file-size when required
This allows fallocate -z to work against a Windows2016 share.
This is due to the SMB3 ZERO_RANGE command does not modify the filesize.
To address this we will now append a compounded SET-INFO to update the
end-of-file information.
This brings xfstests generic/469 closer to working against a windows share.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>